CONTROL OF STRUCTURE AND ELECTRICAL-PROPERTIES OF LEAD-ZIRCONIUM-TITANATE-BASED FERROELECTRIC CAPACITORS PRODUCED USING A LAYER-BY-LAYER ION-BEAM SPUTTER-DEPOSITION TECHNIQUE

It is demonstrated that the structure and electrical properties of Pb( ZrxTi1-x)O3(PZT)-based capacitors, involving RuO2 electrodes, can be c ontrolled by depositing intermediate PbTiO3 (PT) layers at the PZT/ele ctrode interfaces. Three different PZT-based capacitor systems were st udied, namely: (a) RuO2/PZT/RuO2/(100)MgO, (b) RuO2/PZT/PT/RuO2/(100)M gO, and (c) RuO2/PT/PZT/PT/RuO2/(100)MgO. Electrical characterization of capacitor (a), without a PT layer, shows about 71% reduction in rem anent polarization, while those with one (b) or two (c) PT layers pres ent only 34% and 29% decrease in remanent polarization, after 1010 swi tching cycles. Electrical conduction measurements (current density ver sus time) have shown that ion beam sputter-deposited PZT-based capacit ors with or without PT layers present about an order of magnitude (app roximately 6 X 10(-9) A/cm2, at 100 s) smaller dc leakage current, for comparable physical and electrical parameters, than dc leakage charac teristic of PZT sol-gel-based capacitors with RuO2 electrodes produced in our laboratory. Intermediate PT layers may help eliminate the form ation of undesirable second nonferroelectric phases and/or charged def ects at the PZT-electrodes interface in ion beam sputter-deposited PZT -based capacitors, which in tum results in improved electrical propert ies.